Mold for ingots



Oct. 4, 1932. I MATUSCH'KA 1,881,088-

MOLD FOR INGOTS Filed Sept. 9, 1931 A a H '\T---C R, RP 11111; Q RPlnvn/op: MM

Patented Oct. 4, 1932 UNITED STATES BERNHARD MATUSCHKA,' OF TERNITZ,AUSTRIA MOLD For. msocrs Application filed September 9, 1931, Serial No.561,954, and in Austria July 22, 1929.

This invention relates to ingot molds for casting metal blanks forrailway wheels, tyres, and the like, and has for its principal objectthe provision of a mold so constructed that the size of the shrinkagecavity or pipe formed in ingots cast in the mold will be reduced to aminimum and whereby excellent quality and uniformity of the finishedarticle will be ensured.

Further objects of the invention will be apparent from the followingdescription taken in connection with the accompanying drawing, in whichFigure 1 is a vertical sectional view through an ingot mold constructedin accordance'with the principles of the present invention; and Figure 2represents a slightly modified form of mold. I n

For making high-grade cast ingots, it is '1 known that certainfavourable conditions must be adhered to. In order to obtain an ingot ascompact and as free from defects as possible with the most favourablearrangement of the pipe, it is preferable to select an ingot mold whichis wider at its upper end in order to facilitate after-flow of themolten steel into the solidifying ingot. When this measure cannot beadhered to or.in order to further assist it, methods and means are usedwhereby the cooling of the upper part of the ingot is retarded as muchas possible, that is to say, the steel in the ingot head kept molten' aslong as possible. Such methods consist in the lining of the upper partof the ingot mold with refractory materials, orv

the placing of special refractory covers on the ingot'molds. Numerousproposals have been made for improving the effects of these refractorylinings or covers, for cheapenlng their manufacture and for reducing theweight of the useless ingot head. The endeavours aim more particularlyat concentrating the unavoidable shrinkage cavity (pipe) in theuppermost part of the ingot 4 head and causing the said pipe to have aswide and as short a form as possible.

The economical and material advantages of the short and wide form ofpipe concentrated in the upper part of the ingot follow necessarily fromthe nature of the subsequent working by forging or rolling, in which theingots mainly undergo stretching in the direction of-ingot axis. Theportion of the ingot head which must be removed either before or duringmanufacture in order to obtain a perfectly pipe-free ingot body is thenlow in weight, so that the yield is increased.

The requirements which ingots (blanks) for the manufacture of railwaywheel tyres,

rings and like forged pieces must satisfy,

1 with regard to their working up, differ fundamentally from thosediscussed in the foregoing. As is known,.an annular shape is formed byfirst pressing down the blank in the direction of its axis and thenpunching out the middle portion, which operation is intended to remove.the pipe at the same time. For making wheel tyres and the like, thefollowing two ingot molds are usually employed:

The first mold is a more or less cylindrical ingot mold open at the topand has a usually rounded bottom or even no bottom, and the ingot may becast both from below and from the top. -Usually, a refractory cover isnot employed. The wide pipe cavity formed with this ingot mold ispressed (welded) together as well as possible in the subsequent hotworking, that is by pressing down under the hammer or press, but thepipe can never be completely removed however, on punching out. Thissometimes results in very considerable deficiency. The pipe formation,which is not only wide but in addition is mostly also considerablynon-central, renders it unavoidable that portions of the pipe are leftin a more or less welded state in the finished tyre. Finally,theimpurities rising in the steel, such as particles of fireclay andslag, deoxidation and segregation products, collect in this mold in thewide top, that is, in a part of the ingot which later jointly forms thesurface of the finished tyre, and this frequently leads to defects andflaws, rendering the tyre wholly or partly useless. The extensive use ofthis mold is mainly due to the fact that by casting the steel todifferent depths, blanks of any desired weight may be made, arequirement which is a consequence of the large number of rings andtypes of tyres, so that the latter can be made with I one or two sets ofingot molds of diflerent slzes. Y

The difficulties which are caused in manufacture by the non-centralposition of the pipe and by the unsatisfactory surface quality, areoften met by a sharp constriction of the top edge of the ingot mold.This entirely closed mold with the constricted upper part and roundedbottom and in which the ingot may be cast from the top or from thebottom,

This mold has the great disadvantage that one special sort of ingot moldmust be used for each weight of ingot desired,'so that for the usualweights, 12 to 18 different sets of ingot molds must be kept in stock.

The present invention relates to an ingot mold (see Figure 1) which, dueto its peculiar character, surpasses the advantages of both the usualingot molds and also embodies a number of additional advantages without,however, involving the disadvantages described in the foregoing. Theinventor has found that, in order to permit complete removal of the pipeon punching out,'the said pipe must have a narrow and long form insteadof the wide and short form, and hence in order to attain the desiredresult, the method which must be employed is just the opposite to themethod otherwise usual and preferable for the manufacture of ingots forother products. Further, the inventor has found that, by the known useof rings of different height for varying the ingot weight, in connectionwith the new ingot mold in the arrangement shown in Figure 1, veryconsiderable economical and industrial advantages may be secured in thepresent instance.

The ingot moldaccording to the present 'invention is bottle-shaped andpreferably comprises an upper portion or mold member a which is open atthe bottom, and a number of rings B of any height adapted to be placedbelow the mold member a.

The opening of the ingot moldis directed downwardly in such a way thatits shape tapers gradually upward and is considerably bottle-shaped,while passing downwardly into a cylindrical shape.

' One constructional form is, for example, such that the upwardlygradually tapering end continues further in the form ofa plug, which isso dimensioned that it may be knocked oil by hand. g

In the new mold the pipe 0 is located exactly i n the middle. Thegradual taper, which begins quite soon, also causes the pipe to assume avery particularly narrow and long shape so that it can be punched outduring manufacture with the greatest certainty and a minimum of punchingweight.

The gradual taper also causes the rising impurities to be carriedsuccessively towards the middle of the ingot and not to remain caught onthe wall of the ingot mold. The impurities, i. e. fireclay and slagparticles, deoxidation and. segregation products, readily collect in theupper and very narrow part of the new ingot and are readily re moved onpunching out. In particular, in the constructional form described, mostof the impurities are concentrated in the plu which is knocked offbefore the working up, so that such a blank-represents the mostsatisfactory raw product conceivable.

The pointed form of the ingot mold causes,

on solidification of the ingot, a very quick.

and ready separation of the ingot from the mold, w ieh produces a veryfavourable crystallization and has an extraordinarily favourable effecton the durability of the ingot molds.

With regard to the strict requirements imposed on railway rolling stockmade with these ingot molds,,it must be emphasized as a particularadvantage that the ingot mold according to the invention produces ingotswhich, on hot working, undergo in that part which, according toexperience is the worst part of any steel ingot, viz. near the pipe, andin the present instance therefore in the pointed upper end, the mostthorough heating due to the small diameter of the said part, and thegreatest compression or forging due to its greatest height in the ingot.This feature ensures the excellent quality and uniformity of thefinished tyre or forged piece. A special part of the invention are therings R R R and R of any height which, making an exact fit, are placedunder the ingot mold described in the foregoing, as shown in Figure-2 ofthe drawing. In addition to the advantages enumerated, the rings permitblanks of any desired weight to be made with the same ingot mold. Forthis purpose, it is merely necessary to place a suitable number of ringson supports. These rings occupy a small space as they can be piledeasily one on the other. They repre sent only a small weight, as theindividual rings weigh very'little. By this means, 'the casting ofingots of different weights, for which heretofore a stock of ingot moldsof 12 to 18 sorts was necessary, can be effected with 1 to 2 sorts and asuitable number of rings. Finally, the productionof these ringsaccording to the invention is exceedingly simple. It is not necessary tokeep in stock numerous rings of difierent heights.

It suffices to keep in stock long pipes of the internal and externaldimensions of the rings, which dimensions are the same for said pipes ina few hours the necessary substitute rings of the desired height.

If several rings are used for erecting the mold, it is advisable toshape these so that the interior of the mold converges downwardly as isshown in Figure 2 of the drawing. The new mold can be cast from above orfrom below.

I claim 1. An ingot mold for casting metal blanks 'for railway wheels,tyres, and the like, comprising a mold member having an internal cavityof a cross-sectional area gradually tapered upwardly from below a pointsubstantially midway of the upper and lower portions of the member anmerging at its upper end with a relatively constricted neck portion,whereby the shrinkage cavity is narrowed and elongated.

2; An ingot mold for casting metal blanks for railway wheels, tyres, andthe like, comprising a mold member having an internal cavity of a'cross-sectional area gradually tapered upwardly from below a pointsubstantially midway of the upper and lower portions of the member andmerging at its upper end with a relatively constricted neck portion,whereby the shrin age cavity is narrowed and elongated, said mold memberbeing open at the lower end, and an annular element having an innersurface conform'ng substantially to the inner surfaceof the mol memberadjacent its lower end forming a seat for said mold member to increasethe capacity of the mold.

3. An ingot mold for casting metal blanks for railway wheels, t res, andthe like, comprising amold mem er having an internal cavity of across-sectional area gradually tapered upwardly from below-a pointsubstantially midway of the upper and lower portions of the member andmerging at its upper end with a relatively constricted neck portion,whereby the shrinkage cavity is narrowed and elongated, said mold memberbeing open at the lower end, and a plurality of superimposed annularelements gradually reduced in internal cross-section downwardly on whichsaid mold is seated, the cavity defined by the superimposed elementsmerging with the cavity in said mold member.

In testimony whereof I have afiixed my signature.

' DR. B. MATUSCHKA.

